Detergent motor fuel containing the salt reaction product of a paraffinic oil oxidate and a substituted urea

ABSTRACT

Salt reaction product of a paraffinic oil oxide having a Neutralization Number from 55 to 80 and a Saponification Number from 100 to 200 and a substituted urea represented by the formula: IN WHICH X HAS A VALUE FROM 2 TO 4 AND R and R&#39;&#39; are hydrocarbyl radicals having from eight to 20 carbons, and a detergent motor fuel composition containing same.

United States Patent Newman et al.

Oct. 2, 1973 Assignee: Texaco Inc., New York, N.Y.

Filed: Nov. 6, 1970 Appl. No.: 87,600

US. Cl. 44/66, 44/71 Int. Cl. C101 1/18, C101 1/22 Field of Search 44/66, 71;

References Cited UNITED STATES PATENTS 6/1958 Lindstrom et al. 44/66 3,565,592 2/l97l Mehmedbasich 44/71 X Primary Examiner-Daniel E. Wyman Assistant ExamineF-W. J. Shine Attorney-Thomas H. Whaley and Carl G. Reis [57] ABSTRACT Salt reaction product of a paraffiniic oil oxide having a Neutralization Number from 55 to 80 and a Saponiflcation Number from 100 to 200 and a substituted urea represented by the formula:

in which x has a value from 2 to 4 and R and R are hydrocarbyl radicals having from eight to 20 carbons, and a detergent motor fuel composition containing same.

6 Claims, No Drawings DETERGENT MOTOR FUEL CONTAINING THE SALT REACTION PRODUCT OF A PARAFFINIC OIL OXIDATE AND A SUBSTITUTED UREA BACKGROUND OF THE INVENTION 1. Field of the Invention Modern internal combustion engine design and motor fuel compositions are undergoing inportant and substantial changes to meet new strict anti-pollution standards for exhaust gas emissions. A major change in 1 engine design recently adopted is the feeding of blowby gases from the crankcase zone of the engine into the intake air supply to the carburetor rather than venting these gases to the atmosphere as in the past. The blowby gases contain substantial amounts of depositforming substances and are known to form deposits in an around the throttle plate area of the carburetor. These deposits restrict the flow of air through the carburetor at idle and at low speeds so that an over'rich fuel mixture results. This condition produces rough engine idling, stalling and also results in excessive hydrocarbon exhaust emission to the atmosphere.

Motor fuel compositions are undergoing substantial changes. The partial or complete removal of tetraalkyl lead compounds from gasoline is well under way and is bringing about a complete reformulation of the base fuel composition and the octane levels of same. The new fuel composition will require a highly effective detergent additive in order to satisfy the strict antipollution standards.

2. Description of the Prior Art Numerous patents have issued disclosing the use of urea derivatives to effect improvements in gasoline compositions. U.S. Pat. No. 2,373,372 discloses alkylated and arylated ureas for improving the anti-knock value of gasoline. U.S. Pat. No. 2,683,081 discloses N- hydrocarbyl-N |..-.hydroxyphenyl ureas as anti-oxidants for gasoline. U.S. Pat. No. 2,772,148 discloses N-alkyl- N',N'-di(carboxymethyl) urea as a rust inhibitor for hydrocarbon fuels. U.S. Pat. No. 2,965,458 discloses ester-type and acid type petroleum hydrocarbon oxidates and U.S. Pat. No. 3,615,294 discloses a detergent motor fuel composition containing substituted ureas.

SUMMARY OF THE INVENTION A novel class of salt reaction products of a paraffinic oil oxidate and a substituted urea are provided which are useful as carburetor detergents when employed in a liquid hydrocarbonaceous fuel for an internal combustion engine. The saltreaction product comprising a specific paraffinic oil oxidate and the below described substituted urea appears to be unique in its detergency properties.

The fuel composition of the invention mitigates or overcomes the problem of deposits laydown in the carburetor of an internal combustion engine. When a gasoline of the invention is employed in a carburetor which has a substantial build-up of deposits from prior operations, a severe test of the detergency property of the fuel, this gasoline is very effective for removing substantial amounts of these preformed deposits. These properties of the gasoline contribute substantially to improved fuel combustion and cleaner exhaust and emissions to meet prevailingandplanned anti-pollution goals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid paraffinic oil oxidate employed to form the salt reaction product has a Neutralization Number between 55 and and a Saponification Number between l00 and 200. Preferably, this paraffinic oil oxidate has a Neutralization Number between 60 and 80, a Saponification Number between 120 and 165, an un- 0 saponifiable content less than about 55 percent and a viscosity less than 100 SUS at 210F. The oxidate isobtained by air oxidation of a refined paraffinic base lubricating oil having a viscosity between to 350 SUS at F, or more, preferably between to SUS at 100F. The paraffinic base lubricating oil will also have a pour point less than 5F and an aniline point between 214 and 225F. It is generally convenient to employ the liquid oxidate in solution, preferably in a light distillate, mineral, lubricating oil carrier. This facilitates handling and the carrier solution can provide a very suitable medium for forming the salt reaction product. This paraffinic oil oxidate is described in the above-noted U.S. Pat. No. 2,965,458.

The substituted urea component of the salt reaction product has the formula:

in which x has the value of from 2 to 4 and R and R' are hydrocarbyl radicals having from 8 to 20 carbon atoms each. In a preferred embodiment x has a value of 3, and R and R each represent a saturated secondary aliphatic radical having from 10 to 15 carbon atoms.

The salt reaction product of the invention is prepared by reacting the prescribed paraffinic oil oxidate with the prescribed hydrocarbon substituted urea. ln general, suitable proportions of the reactants are employed so that a substantial proportion and preferably all ofthe acid reacting groups in the paraffinic oil mixtureoxidate are reacted to form salt reaction products. The specific proportion of urea to oxidate is determined by their total Base'Number and total Acid Number, respectively. This reaction can be conducted at normal room temperature or at any elevated temperature below the decomposition temperature of either reactant or the reactant mixture. lt ispreferred to conduct this reaction at a temperature ranging from about 60 to 90C but below 100C where amide formation may occur. No further purification of the product is re quired.

Any gasoline suitable for a spark-ignited, internal combustion engine can be used in the practice of this invention. In general, the base fuel will consist of amixture of hydrocarbons in the gasoline boiling range, ie. from about 75 to 450F. The hydrocarbon components can consist of paraffinic, naphthenic, aromatic and olefinic hydrocarbons obtained by thermalor catalytic cracking or reforming of petroleum hydrocarbons.

This base fuel will generally have a Research Octane Number above 85 and preferably above 90.

The salt reaction product of theinvention can be ad vantageously employed in the motorfuel at a concentration ranging from about 0.005 to 0.05 weight percent. The preferred concentration of the additive is from about 0.01 to 0.03 weight percent.

The following examples illustrate the preparation of the salt reaction product of the invention.

EXAMPLE I 180 g (0.60 mole) of N-cocopropylene diamine (commercial Duomeen C) was placed in a 500 ml flask equipped with a thermometer, condenser, magnetic stirrer and a sintered glass tube. 18g (0.30 mole) of urea was added and the mixture heated for three hours at 160C. A slow steady nitrogen flow was maintained to sweep out ammonia being evolved. The nitrogen fiow was continued until the reaction product returned to room temperature. The reaction product was diluted with approximately 600 ml of a 50/50 ether/benzene mixture and washed alternately with 6 X 100 ml of 1.5 N hydrochloric acid. After washing with 6 X 100 ml of 10 percent sodium carbonate, the product was washed with water until the wash was slightly basic, i.e., less than pH 8. The product was dried over CaSO and Na S filtered and the solvent removed by vacuum distillation at 0.5mm Hg over a steam bath.

The N-cocopropylenediamine-urea derivative, also known as 3,3di(cocamino) dim-propylurea, had a total Base Number (ASTM D-664) of 167 (Theory 178) and a nitrogen content of 9.3 percent (Theory 8.9). Duomeen C is an Armour Company having the formula:

where R is an alkyl radical derived from coconut fatty acids.

A paraffinic mineral oil distillate was oxidized by air blowing as described in US. Pat. No. 2,965,458 to produce a liquid oxidate product having an SUS viscosity at 210F of about 82.2, a Neutralization No. of about 73.4 and a Saponification Number of about X37. The foregoing product was dissolved in a mineral oil having a viscosity of I00 SUS at l00F. The resultant solution was filtered and referred to as an oxidate concentrate consisting of about 25 (weight) percent of liquid oxidate in the solution. This concentrate had a TAN (Total Acid Number) of 12.7.

grams of the 3,3 di(cocoamine)-di-n-propylurea and 66 grams of the above oxidate were mixed at room temperature and permitted to react overnight. The resultant solution containing the salt reaction product in an oil solution was suitable as a motor fuel additive.

EXAMPLE ll 5 grams of 3,3'-di(oleylamino)di-n-propylurea having a TBN of 130 were mixed with 51 grams of the oxidate concentrate of Example I and reacted overnight at room temperature to form an oil solution of the salt reaction product.

EXAMPLE [I] 5 grams of 3,3'-di(C sec. alkylamino)di-npropylurea having a TBN of 140 and 55 grams of the oxidate concentrate of Example I were mixed and reacted overnight at room temperature to form an oil solution of the salt reaction product.

EXAMPLE [V 5 grams of 3,3'-di(C sec. alkylamino)dl-npropylurea having a TBN of 178 and grams of the oxidate concentrate of Example I were reacted at room temperature for about 8 hours to form an oil solution of the salt reaction product.

EXAMPLE V 5 grams of 3,3'di(C, -C,. sec. alkylamino)di-npropylurea having a TBN of 205 and grams of the oxidate concentrate of Example I were reacted at room temperature for about 8 hours to form an oil solution of the active salt reaction product.

The salt reaction product of the invention was tested for its effectiveness as a carburetor detergent additive for gasoline in the Chevrolet V-8 Carburetor Detergency Test. This test is run on a Chevrolet V-8 engine mounted on a test stand using a modified four barrel carburetor. The two secondary barrels of the carburetor are sealed and the fuel feed to each of the primary barrels is arranged so that an additive fuel can be run in one barrel and a base fuel run in the other. The primary carburetor barrels were also modified so that they had removable aluminum inserts in the throttle plate area in order that deposits formed on the inserts in this area could be conveniently weighed.

In the procedure designed to determine the effectiveness of an additive fuel to remove preformed deposits in the carburetor, the engine is run for a period of time usually 24 or 48 hours using the base fuel as the feed to both barrels with engine blow-by circulated to the air inlet of the carburetor. The weight of the deposits on both sleeves is determined and recorded. The engine is then cycled for 24 additional hours with base fuel being fed to one barrel, additive fuel to the other and no blow-by to the carburetor air inlet. The inserts are then removed from the carburetor and weighed to deter mine the difference between the performance of the additive and non-additive fuels in removing the preformed deposits. After the aluminum inserts are cleaned, they are replaced in the carburetor and the process repeated with the fuels reversed in the carburetor barrels to minimize differences in fuel distribution and barrel construction. The deposit weights in the two runs are averaged and the effectiveness of the base fuel and of the additive fuel for removing deposits expressed in percent.

The base fuel employed in the following examples was a premium grade gasoline having a Research Octane Number of lOl and contained 3 ml of tetraethyl lead per gallon. This gasoline consisted of about 25.5 percent aromatic hydrocarbons, 20 percent olefinic hydrocarbons and 54.5 percent paraffinic hydrocarbons and boiled in the range from about 89F to 362F.

The carburetor detergency test results obtained from the base fuel containing the salt reaction products described above are set forth in the following Table. The additive-containing fuels contained 5 PTB (pounds per one thousand barrels of fuel) of the urea and enough of the oxidate as a solution in mineral oil to completely neutralize the urea.

TABLE l Chevrolet Carburetor Detergency Test Deposit Removal Deposit Deposit Run Fuel Build-up Removed Effect mg* mg ive l Base Fuel 25.6 0.7 3 2 Base 71 PTB Example I 26.6 13.6 SI 48 3 Base Fuel 25.6 L 4 4 Base 56 PTB Example II 29.2 17.9 61 57 5 Base Fuel 25.8 6.2 24 6 Base 60 PTB Example lll 25.9 14.7 57 33 7 Base Fuel 22.0 l.l" 5 8 Base +75 PTB Example W 21.2 16.7 79 84 9 Base Fuel l9.5 -3.6 -l8 10 Base 85 PTB Example V 20.4 l3.6 67 85 Built up with base fuel Additional deposits formed hydrocarbons in the gasoline boiling range containing a minor carburetor detergent amount of the neutral salt reaction product formed at a temperature from 60 to 90C. of a substituted urea represented by the formula:

in which x has a value from 2 to 4 and R and R are hydrocarbyl radicals having from eight to 20 carbon atoms and a paraffmic oil oxidate having a Neutralization Number from 55 to and a Saponification Number from l00 to 200.

2. A motor fuel composition according to claim 1 containing from about 0.005 to 0.05 weight percent of said salt reaction product.

3. A motor fuel according to claim 1 in which said substituted urea is 3,3-di(oleylamino)-di-npropylurea.

4. A motor fuel composition according to claim 1 in which 1: has a value of 3 and R and R are aliphatic by drocarbon radicals having from 10 15 carbon atoms.

5. A motor fuel composition according to claim 1 in which said substituted urea is 3,3'-di(cocoamino)di-npropylurea.

6. A motor fuel composition according to claim 1 in which said substituted urea is 3,3' di-(C -C sec. alkylamino)-di-n-propylurea. 

2. A motor fuel composition according to claim 1 containing from about o.005 to 0.05 weight percent of said salt reaction product.
 3. A motor fuel according to claim 1 in which said substituted urea is 3,3''-di(oleylamino)-di-n-propylurea.
 4. A motor fuel composition according to claim 1 in which x has a value of 3 and R and R'' are aliphatic hydrocarbon radicals having from 10 - 15 carbon atoms.
 5. A motor fuel composition according to claim 1 in which said substituted urea is 3,3''-di(cocoamino)di-n-propylurea.
 6. A motor fuel composition according to claim 1 in which said substituted urea is 3,3''-di-(C10-C14 sec. alkylamino)-di-n-propylurea. 